Apparatus for telephonic systems.



Patented Dec. I9, |899. F. B. COOK. 1 APPRATUSFOR TELEPHONIE SYSTEMS.

(Application filed Nov. 30, 1894.)

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(No Model.)

Patented Dec. I9, |899.

F. B. COOK.

APPARATUS FDR TELEPHONIE SYSTEMS.

(Application led Nov. 80, 1894.)

2 sheets-sheet 2.

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PATENT FRANK B. COOK, OF CHICAGO, ILLINOIS.

APPARATUS FOR TELEPHONICA SYSTEMS.

SPECIFICATION forming part of Letters Patent No. 639,526, dated December 19, 1899.

I Application filed November 30, 1894. Serial No. 530,441. (No model.)

T0 all whom, it may concern.:

Be it known that I, FRANK B. COOK, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Apparatus for Telephonie Systems, of which the followingis a specification.

My invention relates to improvements in apparatus used in telephone systems, and more particularly to that class known as automatic exchanges, and is designed to provide means for telephone connections and conversations between any two or more of a number of telephone-stations without necessitating the establishment and maintenance of a central office, the means of connecting the circuits and maintaining conversation between any two stations being provided at each station.

My invention also relates to an improvement in circuit arrangement and disposition and relative arrangement therein of apparatus whereby it becomes necessary to Iirst remove the hand-telephone from the switchsupport before signaling with the generator, and as the natural tendency when removing the telephone will be to place it to the ear and listen before signaling the serious annoyances often experienced by one party who is using a line and holding a conversation being interrupted by another party on the same line where the present system, which admits of sending a signal before removing the telephone from its support is used, will be entirely overcome.

My invention consists' in the provision of a signaling-generator which is positioned in the telephone-circuit and maintained in circuit with the receiver and transmitter, the generator beingprovided with a shunt to cut out the resistance of its armature-windings, and a telephone-circuit switch being provided which opens and closes the telephone-circuit, including the generator, the circuit being maintained normally open when the handtelephone is in its position of disuse, thus requiring the removal of the hand-telephone from its support, and consequent closing of the circuit by the switch, in orde'r to talk or signal over the circuit, and a signal-indicator located in abranch circuit.

My invention also consists, further, in the provision of a shunt-circuit around the tele'- phone which is normally open and means for closing the shunt-circuit when it is desired t0 extend a signal, thereby diverting the signaling-current, so that no loud and disagreeable noise shall be set up in the hand-receiver at the ear of the person using the apparatus.

My invention also consists in the provision of a shunt-circuit about the telephone which has included therein a resistance relatively less than that of the telephone,'whereby a portion only of the calling-generator circuit is diverted about the telephone, thus permitting a portion of the calling-current to pass through the telephone, this arrangement being important in a case where the signal-indicator of the station is responsive only to incoming signals, that portion of the callinggenerator current passing through the telephone at the ear of the user of the apparatus indicating by the sound thereof that a call is being extended, which sound is not disagreeably loud.

My invention has certain other objects in view; and it consists in certain other features, which will be hereinafter set forth, and pointed out in my claims, reference being now had to the accompanying drawings, in which* Figure 1 is a diagrammatic view of the circuit connections and arrangements employed to carry out myinvention. Fig. 2 is a detail View'of the .means by which the call-generator shaft is shifted laterally to operate the generator and telephone shunts. Fig. 3 is a View of the face-plate for the reception of the switch-key. Fig. 4 is a side view of the contact-making springs and connections operated by the switch-key. Fig. 5 is a plan View of the same. Fig. 6 is an end view of the same. Figs. 7 and 8 are detail views of the key.

Referring now to the drawings andhaving special reference to Fig. 1, ity will be observed that main-line wires (designated as A2 B2 C2) are used in connecting the various stations together, these wires being ordinary line-wires separated and supported in the usual manner of aerial-wire construction. At each station, as at A, B, and C, lateral branches connect the main-line wires and the common return-wire E, which accompanies the main-line wires throughout their entire length, with the station equipment. These branch connections are made by means of the special form of cable to be hereinafter more fully described, the insulated conductors of the cable being connected to the line-Wires and the other conductors to the return in the usual manner, or, if desired, an earth connection may be used at each station in lieu of the common return E, the latter being only provided to improve the Working of the lines when subjected to external electrical disturbances. In the case of a metallic circuit the common return or ground Would be replaced by the individual return.

I will noW proceed to a description of the construction of the apparatus by which the circuits are established at a given station with any other station, the apparatus being shown in Figs. 3 to S, inclusive, and consisting of the face-plate 2, of insulating material, having a number of elongated perforations therein at 22 to admit the key 23, having the ears 24, of insulating material, and the stoppin 25, mounted on the shank 20. A number of spring contact-strips 27 are provided, arranged in sets diagonally opposite each other and each setconnected,iespectively,with comlmon conducting or terminal strips 2S and 2S,

any pair of which strips 27 are adapted to be pressed into contact with a pair of the terminal posts 29 and 30 by the insertion of the key 23 in the keyholes 22 and turning the same at a right angle to the position in which it is inserted. The spring contact-strips 27 are preferably formed on the same piece of metal With the conducting terminal strips 2S and 2S. These strips are secured on either side of the square bar or base of insulation 70, the Whole being held in position relative to the face-plate 2l by means of insulated blocks 7l, secured to terminal posts. The free end ofthe spring-contacts 27 normallystand away from the terminal posts. The terminal posts 29 and 30, at which the lateral branches from the main lines terminate, are mounted on the face-plate 21 in pairs diagonally opposite each other, a keyhole 22 being centrally located between each pair of posts. A pair of spring contact-strips 27 are also located between each pair of posts, being placed intermediate between the keyhole and the posts. Thus when thekey is inserted in any keyhole and turn ed ataright-angleacontact is made between that pair of terminal posts and its pair of contactstrips. These pairs of contact-strips and terminal posts are designated by the symbols X, A, B, and C on the face-plate 21, X representing the local-station connection or common answering-switch, and A, B, and C representing main-circuit-switch connections, the terminal posts of theselatter being by means of the lateral branches connected to the main lines. Each station is designed to be connected to some one of these main circuits, and at that station the pair of local terminal posts X are connected by branch Wires with the terminals ofthe main circuit to which it is assigned. Thus at station A the posts X and A are connected together, at station B, X and B, and at station C, X and C. Sometimes several different stations are assigned to the same circuit, it being practicable to have as many as six, in which case different signals must be given for each station on the circuit.

Referring again to Fig. 1, it will be observed that the signal-bells 57 are connected by leads 56 and 5S to the X terminal posts at each station; also, that conducting-strip 2S is connected by lead 45 to the automatic telephone-switch 3S, which switch operates upon the removal of the hand-telephone to close the primary circuit of the transmitter and also close the circuit from lead 45 through the transmitter and receiver and generator to lead 42, connected to conducting-strip 28, and upon the replacement of the telephone the circuits are opened at the switch.

I will now proceed to describe the manner of operating my system, assuming that for this purpose station A desires to communicate with station B. The party at station A inserts the key 23 in the keyhole 22 (designated by the symbol B) and, giving it a quarter-turn, connects the leads 42 and 45 with the main line B2 and common return E by causing a pair of contact-strips 27 of the conducting-strips 2S and 2S to contact with the pair of terminal posts of that circuit. After turning the key the hand-telephone 37 `is removed from the hook of the switch-lever 38 and placed to the ear to listen and learn if B circuit is being used. The circuit may be traced as follows from main line B2 to terminal post at B, conducting-strip 2Sn and lead 42 to spring-contact 43, which is always in contact with one end of the armature-Windings of the generator44. Normally the shaft 62 of the generator is also in contact With the spring 43, and as the other end of the armature-windings is connected in the usual manner to the frame and shaft the generator is short-circuited or shunted, andthe resistance of the armat ure-windings not included in the present circuit. Continuing from spring 43 the circuit is through the generator-frame t0 lead 4U, thence to and through the receiver 37 to lead 47, branch 50, secondary of the induction-coil 5l, lead 52, spring-contactil, switchlever 38, lead 45, and conducting-strip 28, thence through the terminal posts to the aeturn side of the circuit. Upon discovering that B circuit is not being used the crank of the generator is rotated, causing the shaft G2, in a manner to be hereinafter more fullydescribed, to move laterally, breaking contact with spring 43, thus opening the generatorshunt and including the armature-windings in the line-circuit and, moving still farther, make contact with contact-strip 49, closes the normally-,open telephone-shunt. The continued rotation of the crank caused the generator-armature by means of the gear-Wheels to also rotate and generate a current, which, passing out upon the line and through the IZO IZS

helices ofthe signal-bell 57 at station B, attracts attention by sounding an alarm. This circuit may be traced as follows: Starting from one side of the generator, the current has, for a purpose to be hereinafter more fully set forth, at first a divided path, a portion passing from the frame to lead 46, to and vthrough receiver 37 to lead 47, and another portion passing from the frame by means of the shaft 62 and contact 49 to and through the resistance-coil F and lead 48 to the meetingpoint 50, where the telephone shunt-circuit joins the lead 47, thence by lead 5l to and through the secondary of the transmitter induction-coil to lead 52, contact-strip 4l ,switch 38, lead 45, conducting-strip 28, terminal post B, return E, to terminal post X of station B, lead 56, to and through the signal-bell 57, lead 58, to main lino B2, 'thence back to terminal post B-of station A, conducting-strip 28, lead 42, and spring-contact strip 43 back to the vgenerator and starting-point. Upon the crank-being released the shaft 62 breaks cont-act with strip 49,. thus .opening the telephone-shunt, and makes contact With spring 43, thus closing the generator-shunt and cutting the generator out of the-line-circuit. Attention at station B being attracted by the ringing of the bells, the subscriber at that station inserts the switch-key in the keyhole X and gives it a quarter-turn, which results in the ears 24 vof the key pressing against the pair of spring-contacts 27 and making a contact betweenthem and the pair of terminal posts X. He then removes the hand-telephone from the switch-hook and, placing it to his ear, enters into conversation with station A. The telephone-circuit may be traced as follows, starting from the receiver at station A: receiver 37, lead 46, generator 44, spring 43, lead 42, strip 28, post B, line B3, to post X at station B, strip 28, lead 42, spring 43, generator 44, lead 46, to and through telephone 37, lead 47, lead 5l, to and through induction-coil to lead 52, contact '41, switch 38, lead 45, strip 28, post X, thence by returnwire E to post B of station A, strip 28, lead 45, switch 38, contact 4l, lead 52, to and through the induction-coil, lead 5l, to lead 47, and thus back to the starting-point.

The local transmitter-circuit may be traced as follows: from battery G to lead 53, contact 40, connecting-plate 39, contact 4l, lead 52, lead 54, to and through the primary of induction-coil to lead 55, transmitter H, and lead 59 back to the battery.

Upon completion of conversation the subscribers at stations A and B replace the receivers upon the switch-supports and the `weight of the receivers depress the lever,

causing the insulation 41a to press against the spring contact-strips 40 and 4 1 and break the contacts between them and plate 39 and opening the local as well as the main circuit at this point. The keys should also be removed from the switches; but this is not essential.

Station A can in like manner call station C by placing the key in the C switch, and thus any station may signal and talk with any other station, or, if desired, several stations may by arrangement converse together upon any agreed circuit.

It should be observed that while station A was talking with station B the signal-bell and circuit assigned station A formed no part ofthe connected circuit. Therefore any other station could signal station A without interrupting the conversation between A and B.

Although l have herein described the circuit arrangement and disposition of signaling and talking apparatus in conjunction with automatic exchanges, I do not wish to beunderstood as limiting all my claims to such conjunctive use,as it is evident that my invention possesses features independent of such a use, which features I will now outline.

It will be observed that the transmitter, receiver, and generator are always in the same relative position to each other and always in the same circuit invseries, with a shunt normally closed around the generator-armature, which shunt is automatically opened and closed by the driving mechanism of said generator. Thus the generator is included in the telephone-circuit. y

As hereinbefore stated, both the generator and telephone shunts are caused to open and close by the lateral movement of the crankshaft. This shaft 62 is provided with a disk upon its end for contacting with spring 43, attached to the end 62, and extending through the tube 6l, in whichit-fits easily, is the spindle 62, and attached to the spindle is the collar 62h, this colla-r serving the double purpose of a stop for the crank,which is threaded upon the end of the spindle or shaft, and also serving to regulate the length of the lateral movement of the spindle. Attached to the tube 6l is the collar 61"L and also the gear-wheel 61h, these being placed on either side of the frame 63, which supports the shaft and prevents any lateral movement in the tube, but allows it to revolve freely in the bearings. One end of this tube, as shown at 64, is V- shaped to correspond with the enlarged portion of the shaft62, thus forming a clutch. Between the collar 62b and the wheel 6l is a spiral spring 65,which, being under tension, tends to push the spindle and tubey in opposite directions. When the shaft 63 is rotated, it will, by reason of the V-clutch, move laterally until the collar 62b comes against wheel 61h, preventing further lateral movement and forcing the clutch to engage and causing the tube, and consequently the gear-Wheel, to rotate with the shaft. When the power which `causes the shaft to rotate is removed, the

spring65 automatically restores the parts to the normal position shown in Fig. 2.

YVhen the hand-telephone 37 is on the switch 38,the telephone and generator circuit is open, and should the generator-armatu re be rotated no current would pass to line, since the cir- IOS) IIO

cuit is open at the switch. In order to extend a call, it is first necessary to close the telephone, which is also the generator-circuit, by removing the receiver from the switch-hook, when the switch will automatically close the circuit. When removing the receiver to extend a call, the person so doing will naturally place the same to the ear and listen before sending a signal, this feature being especially important on party-circuits to avoid interruptions.

As hereinbefore shown and described, the signal-bell at each station is included in a circuit independent of the other apparatus, and therefore in extending a call the signal-bell of the calling-station will not, as in other magneto call-bells, indicate such by the ringing of the bell. This loud ringing of the bell is in some cases objectionable, and I overcome the objectionable feature by using the receiver to indicate that the generator-current is passing to line.

To avoid setting up the disagreeably-loud noise in the receiver which a strong generator-current would cause, I provide the shuntcircuit 4S about the receiver. With this circuit I am able, by increasing or reducing the resistance of the shunt, to regulate the current which may pass through the receiver. It is obvious that both receiver and trans mitter may be shunted, if desired, and the generator connected lnore directly to line.

It is also obvious that the switch shown in Figs. 3 to S may be used -in connection with other than automatic exchange-circuits.

Having thus described myinvention, what I claim as new therein, and desire to secure by Letters Patent, is-

l. In a telephone apparatus, a normallyopen telephone-circuit, a callin g-gen erator included therein, a generator-shunt operated automatically by the driving mechanism for said generator, a telephone set in the telephone-circuit and in series with the generator and the line, and a telephone-switch controlling the telephone-circuit by closing and opening the same to establish and disestablish the line-circuit relatively to the generator and the telephone set whereby the telephone must be removed from its support in order to ring together with a signaling-indicator in a branch circuit.

2. In a telephone-station, a generator, telephone apparatus and a normally-open branch circuit around the receiver having a suitable resistance therein and means operated by the generator for automatically closing the branch circuit so that a portion only of the calling-current passes through the receiver.

3. In a telephone system, a generator, telephone apparatus and a branch circuit around the receiver having a resistance less th an that of the receiver, said generator being adapted to close the branch circuit so that a portion only of the callin g-current passes through the receiver.

4. In a telephone-station, the combination with a normally-open telephone-circuit, of a callin g-gencrator positioned in the telephonecircuit a generator-shunt operated automatically by the driving mechanism for said generator, a telephone set included in the telephone-circuit in series with the generator and the line and a switch to close and open the telephone-circuit together with a branch circuit around the telephone and means for closing the same.

5. In a telephone-station, the combination with a normally-open telephone-circuit, of a calling-generator positioned in the telephonecircuit, an automatically-operated shunt for said generator, a telephone set included in the telephone-circuit in series with the generator and the line and a switch to close and open the telephone-circuit together with a branch circuit around the receiver controlled by the generator.

6. In a telephonestation, a normally-open telephone-circuit, a calling-generator, an automatically-operated shunt for the generator, a telephone set included in the telephone-circuit in series with the generator and the line, a switch forclosing and opening the telephonecircuit, a signal-receiving indicator operated only by a currentfrom some other station, a branch circuit and a resistance included therein relatively lower than that of the receiver, which branch circuit extends around the said receiver and is closed only when the genera tor is operated.

7. In a telephone system, means for establishing communication between the stations, comprising line-wires extending between the stations, designating-symbols for all the stations of the system arranged at each station in proximity to points for establishing contact, the line-wires of each station being connected with a terminal in proximity to its designating-symbol, a signal-bell circuit at each statiouincluding the signal-bell, the sig- Daling-circuit of each stat-ion being connected with the line-wire of that station and with a common return whereby any station may be signaled when a key is inserted at the callingstation near the designating-symbol of ythe stat-ion to be called, together with a signalingcurrent generator and telephone apparatus in circuit with conductor-terminals,one of which is adapted to be connected with the terminal point of any line-wire and the other of which is adapted to be connected with the common return the signal-bell circuit being independent ofthe circuit or circuits including the generator and telephone apparatus and said generator being adapted to automatically establish and disestablish its circuit, together with a normally-open branch circuit around the receiver having a suitable resistance therein and means operated by the generator for automatically closing the branch circuit so that a portion only of the calling-current passes through the receiver.

8. In a telephone system, means for estab lishin g communication between stations,com

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prising line-wires extending between the stations, designating-symbols for all the stations of the system arranged at each station in proximity to points for establishing contact, the line-Wire of each station being connected with a terminal in proximity to its designatingsymbol, a signal-bell circuit at each station including the signal-bell, a pair ot' terminal conductor-plates with which the line-circuits are adapted to be connected byakey, the signaling-circuit at each station being connected with the pair of terminal plates of that station and adapted to be Aconnected with the line-Wire terminals by a key, together with a branch circuit around the hand receiver, which branch circuit is controlled by the generator. A

9. A switch, comprising a multiplicity of spring-contacts, consisting of a face-plate of insulating material, a number o f contact terminal rods supported by the face-plate, a base of insulating material and the sets of springcontacts supported by the base and extended therefrom, together With perforations in the face-plate opposite each pair of terminal rods and sets of contact-springs to permit the insertion of a key to connect the said contactsprings to their respective terminal rods.

l0. In a telephone apparatus, tWo shunts, one around the generator only which is normallly closed, and the other around the telephone Which is normally open and a switch common to both shunts for alternatelypoperating them.

11. In a telephone apparatus, two shunts, one around the generator which is normally closed, and the other around the telephone Which is normally open, and a generator, by the operation of which both the normallyclosed generator-shunt is opened andthe normally-open telephone-shunt is closed.

In testimony whereof I affix my signature in presence of two Witnesses.

FRANK B. COOK.

Witnesses:

CHARLES C. BULKLEY, W. T. ToMPKrNs. 

